Due to an increase of various types of multimedia content and high-capacity content such as High Definition (HD) content or Ultra High Definition (UHD) content, data congestion in a network has become serious in the recent broadcasting and communication environment. The data congestion leads to failure of content transmission from a sender (e.g., Host A) to a receiver (e.g., Host B) and loss of part of the content.
Since data is generally transmitted in packets, data loss occurs on a packet basis. If data is lost in the network, the receiver cannot receive a data packet and thus cannot obtain data from the lost packet. Therefore, a user may experience inconvenience in various ways including degraded audio quality, degraded video quality, screen failure, loss of subtitles, file loss, and the like. Accordingly, there exists a need for a technique for recovering data lost in a network.
To support recovery of data lost in a network by a receiver, a source packet block may be constructed with a predetermined number of data packets of variable lengths, referred to as source packets, and repair information such as parity data or repair packets may be added to the source packet block by Forward Error Correction (FEC) coding. In the presence of lost data, the receiver may decode the data using the repair information.
In the process of generating parity data or repair packets from a source packet block by FEC coding, a source symbol block including source symbols of the same length is constructed from the source packet block, a repair symbol block including repair symbols is generated by FEC coding of the source symbol block, and repair symbol blocks are converted to FEC repair packets, and the FEC repair packets and FEC source packets being source packets which have been FEC-encoded are transmitted, as FEC packets. Since each of the source packets has a variable length and the source symbol block includes source symbols of the same length, padding data is required in generating the source symbol block from the source packet block. Therefore, a method for efficiently generating a source symbol block is needed. Further, there is a need for an in-band signaling method for transmitting an error correction signal (i.e., a source FEC payload IDentifier (ID)) in each source packet of an error correction packet block and transmitting an error correction signal (i.e., a repair FEC payload ID) in each repair packet.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.